<template>
	<!-- 筛选区 -->
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a  @click="changeBrand(p.id)" :class="{active:filterData.selectedBrand===brand.id}" href="javasript:;" v-for="brand in filterData.brands" :key="brand.id">{{brand.name}}</a>
      </div>
    </div>
    <div class="item" v-for="p in filterData.saleProperties" :key="p.id">
      <div class="head">{{p.name}}：</div>
      <div class="body">
        <a @click="changeAttr(p,prop.id)" :class="{active:p.selectedProp===attr.id}" href="javasript:;" v-for="attr in p.properties" :key="attr.id">{{attr.name}}</a>
      </div>
    </div>
  </div>
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px"  />
    <XtxSkeleton class="item" width="800px" height="40px"  />
    <XtxSkeleton class="item" width="600px" height="40px"  />
    <XtxSkeleton class="item" width="600px" height="40px"  />
    <XtxSkeleton class="item" width="600px" height="40px"  />
  </div>
</template>
<script>
import { findSubCategoryFilter } from '@/api/category'
import { useRoute } from 'vue-router'
import { ref, watch } from 'vue'
export default {
  name: 'SubFilter',
  setup (props,{emit}) {
    // 1. 获取数据
    // 2. 数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
    // 3. 完成渲染
    const route = useRoute()
    //监听二级类目ID的变化获取筛选数据
    const filterData = ref(null)
    const filterLoading = ref(false)
    // 4. 分类发生变化的时候需要重新获取筛选数据，需要使用侦听器
    watch(() => route.params.id, (newVal) => {
      // 当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
      if (newVal && route.path === ('/category/sub/' + newVal)) {
        filterLoading.value = true
        newVal && findSubCategoryFilter(route.params.id).then(data => {
        // 品牌全部
          data.result.selectedBrand = null
          data.result.brands.unshift({ id: null, name: '全部' })
          // 销售属性全部
          data.result.saleProperties.forEach(p => {
            p.selectedProp = undefined
            p.properties.unshift({ id: null, name: '全部' })
          })
          filterData.value = data.result
          filterLoading.value = false
        })
      }
    }, { immediate: true })

    //获取筛选参数的函数
    const getFilterParams = () => {
      const filterParams = {}
      const attrs = []
      //品牌
      filterParams.brandId = filterData.value.selectedBrand
      //销售属性
      filterData.value.saleProperties.forEach(p => {
        const attr = p.properties.find(attr => attr.id === p.selectedProp)
        if (attr && attr.id !== undefined) {
          attrs.push({ groupName: p.name, propertyName: attr.name })
        }
      })
      if (attrs.length) filterParams.attrs = attrs
      return filterParams
    }

    //1.记录当前选择的品牌
    const changeBrand = (brandId) => {
      if (filterData.value.selectedBrand === brandId) return 
      filterData.value.selectedBrand = brandId
      emit('filter-change', getFilterParams())
    }
    //2.记录你选择的销售属性
    const changeAttr = (p, attrId) => {
      if (p.selectedProp === attrId) return
      p.selectedProp = attrId
      emit('filter-change', getFilterParams())
    }

    return { filterData, filterLoading,changeBrand, changeAttr }
  }
}
</script>
<style scoped lang='less'>
  // 筛选区
  .sub-filter {
    background: #fff;
    padding: 25px;
    .item {
      display: flex;
      line-height: 40px;
      .head {
        width: 80px;
        color: #999;
      }
      .body {
        flex: 1;
        a {
          margin-right: 36px;
          transition: all .3s;
          display: inline-block;  
          &.active,
          &:hover {
            color: @xtxColor;
          }
        }
      }
    }
  }

.xtx-skeleton {
    padding: 10px 0;
}
</style>